All categories

3 years ago

2. Solve the following system. Show all your work. {3x - 2y + 2z = 30 {-x + 3y - 4z = -33 {2x - 4y + 3z = 42

1 answer:

6 0

From the system of equations, we have 3 unknowns and 3 equations. Therefore, it can be solved.

3x - 2y + 2z = 30 (1)
-x + 3y - 4z = -33 (2)
2x - 4y + 3z = 42 (3)

We can write equation 2 x as a function of y and z and substitute the new equation to the other equations.
x =3y - 4z + 33 (2)

3 (3y - 4z + 3) - 2y + 2z = 30 (1)
2 (3y - 4z + 3) - 4y + 3z = 42 (3)

We simplify and solve the equations and we get values,

x = 4
y = -7
z = 2

You might be interested in

Q(a+1) - 2q(a) if q(x) = x²+3x+4

siniylev [52]

$q(x) = {x}^{2} + 3x + 4$

_________________________________

Step(1)

To find q(a) we just need to put a instead of x in q(x) function.

Let's do it...

$q(a) = {a}^{2} + 3a + 4$

Multiply sides by -2 :

$- 2q(a) = - 2( {a}^{2} + 3a + 4)$

$- 2q(a) = - 2 {a}^{2} - 6a - 8$

_________________________________

Step (2)

To find q(a+1) we just need to put a+1 instead of x in q(x) function.

Let's do it...

$q(a + 1) = ({a + 1})^{2} + 3(a + 1) + 4 \\$

$q(a + 1) = {a}^{2} + 2a + 1 + 3a + 3 + 4 \\$

$q(a + 1) = {a}^{2} + 5a + 8$

_________________________________

Step (3)

$q(a + 1) - 2q(a) =$

${a}^{2} + 5a + 8 - 2 {a}^{2} - 6a - 8 = \\$

$- {a}^{2} - a = - a(a + 1)$

And we're done.

Thanks for watching buddy good luck.

♥️♥️♥️♥️♥️

8 0

3 years ago

You ENTER a room and there are 34 people, you KILL 30. How many are left in the room?

lozanna [386]

Answer:4

Step-by-step explanation:

34-30=4

8 0

3 years ago

Read 2 more answers

Given a function <img src="https://tex.z-dn.net/?f=f%28x%29%3D3x%5E4-5x%5E2%2B2x-3" id="TexFormula1" title="f(x)=3x^4-5x^2+2x-3"

Levart [38]

Answer:

$\huge\boxed{f(-1) = -7}$

Step-by-step explanation:

In order to solve for this function, we need to substitute in our value of x inside to find f(x). Since we are trying to evalue f(-1), we will substitute -1 in as x to our equation.

$f(-1) = 3(-1)^4 - 5(-1)^2 + 2(-1) - 3$

Now we can solve for the function by multiplying/subtracting/adding our known values.

Starting with the first term to the last term:

$3(-1)^4 = 3$

WAIT! How is this possible? $-1^4 = -1$ (according to my calculator), and $3 \cdot -1 = -3$ , not 3!

It's important to note that taking a power of a negative number and multiplying a negative number are two different things. Let's use $-2^2$ as an example.

What your calculator did was follow BEMDAS since it wasn't explicitly told not to.

BEMDAS:

- Brackets

- Exponents

- Multiplication/Division

- Addition/Subtraction

Examining the equation, your calculator used this rule properly. Note that exponents come over multiplication.

So rather than being "-2 squared" - it's "the negative of of 2 squared."

Tying this back into our problem, the squared method would only be true if it looks like $-1^4$ . However, since we're substituting in -1, it looks like $(-1)^4$ , so the expression reads out as "-1 to the fourth."